This application relates to mounting, cooling and controlling a number of distinct types of power electronic circuits interconnected to form unique functions such as motor controllers in a common rack.
Motor controllers typically include a number of functions, namely, 1) a power conversion function, 2) a control function, 3) a filter magnetics function and 4) a thermal management function.
The power conversion function contains a number of different components built around the power switching devices. The control function commands the power switches in the conversion function to operate at certain frequencies and modes to achieve power conversion. The switching of high voltage and currents at high frequencies in the conversion function is accompanied by electromagnetic noise and power quality effects necessitating the filtering function in the motor controller. The filters include inductors, transformers and other magnetic structures. The conversion function and the filtering function dissipate significant amount of heat that the thermal management function must control. In the conversion function, the power switching devices are the most power dissipative and therefore require carefully designed thermal management techniques.
These power devices with their thin structures and flat thermally conductive baseplates lend themselves to cold plate cooling. A cold plate typically is a heat exchanger that receives a circulating cooling fluid.
However, transformers, filters or inductors, have a relatively large height, and thus are not adequately cooled by cold plates. Such systems are often cooled by a flooded chamber, or spray cooling of a fluid.
In addition, in general, all of the several functions in the motor controllers have been housed within a single unit. Thus, it has not been possible to provide optimum cooling. Instead, the combined systems have all typically been cooled by one cooling method or the other (cold plate or submerged/sprayed) and not combined.